Dispenser for flexible sheet material and a perforating mechanism adapted to be used therein

ABSTRACT

A mechanism for perforating a web of flexible sheet material which is adapted to be used in a flexible sheet material dispenser, said mechanism comprising; a rotatably mounted roller, a rotatably mounted knife positioned adjacent the roller and having a radially outward portion defining a cutting edge for perforating the web as the web passes between the roller and the knife, the roller being operatively connected to the knife for synchronous rotation therewith and having a slot therein for receiving the radially outward knife portion as the knife rotates past the roller, and means associated with the knife for orienting the cutting edge substantially in the direction in which the radially outward knife portion moves with respect to the web during the entrance of the portion into the slot so that when the portion enters the slot the cutting edge will effectively perforate the web.

1,467,481 9/1923 Juline.......................... 83/678X 2,278,0293/1942 Walsh et al. 83/345 Primary Examiner-James M. MeisterAttorney-Birch, Swindler, McKie & Beckett ABSTRACT: A mechanism forperforating a web of flexible sheet material which is adapted to be usedin a flexible sheet material dispenser, said mechanism comprising; arotatably mounted roller, a rotatably mounted knife positioned adjacentPaul W. Jespersen; Edward L. Bump, Stamford, Conn. 793,808 Jan. 24, 1969Georgia-Pacic Corporation Portland, Oreg.

AND A PERFORATING MECHANISM ADAPTED U mted States Patent [72] Inventors[2l Appl. No.

[22] Filed [45] Patented Apr. 20, 1971 [73] Assignee [S4] DISPENSER FORFLEXIBL SHEET MATERIAL Patented April 20, 1971 3,575,328

` 11 Sheets-Sheet l \l m N FEnT I' N" l "N l ,j N N o ,f /f o 9 l N 1'Il OW will mmm um@ 9 (9 1 O/V' rc2 g w s2 i PAUL W. JESPERSEN, EDWARD L.BUMP ATTOR NE YS INVENT ORS Patented April 20, 1971 l1 Sheets-Sheet 2Lall lllli INVENTORS ATTORNEYS PAUL w. JEsPERsEN, EDWARD L. BUMPVPatented April zo, 1971 v11 Sheets-Sheet 5 KNIFEEDGEPATH 280 PatentedApril 20, 1971 3,575,328

11 Sheets-Sheet u INVENTORS g PAUL w. JEsPERsEN,

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ATTORNEYS Patented" April 20, 1971 11 Sheets-Sheet 6 Patented April 20,1971 11 Sheets-Sheet '7 44 Flags INVENTORS PAUL W. JESPERSEN,

EDWARD L. BUMP 3%@ @icwww/a ATTORNEYS Patented April zo, 1971 l1Sheets-Sheet 9 303 Flc-3.19

INVENTORS S %m f N m wm SP nu RM 4W EU `A PB l S .w C Wm J, LA M Um M MEmi M B 255 /L 246 FIGL Paume Apri 0, 19N 3,575,326

11 Sheets-Sheet l l INVENTORS PAUL W. JESPERSEN,

BY EDWARD L. BUMP IIIJIISIIIIENIEIII FOIIII FILE ilitllLlE @IIIIEIETMA'I'EL AND A IIIIIEIkFOIIIA'II'IIIIG It/IFCIIANISlI/I {IIDID TO BIEUSED 'I'IIIFIWIEIIN BACKGROUND OF THE INVENTION l. Field of theInvention This invention relates to dispensers, and specifically to aflexible sheet material dispenser and a mechanism -adapted to be usedtherein for perforating a web -of flexible sheet material.

DESCRIPTION OF THE PRIOR ART Dispensers for flexible sheet material,such as paper toweling, have long been known which include mechanismsfor perforating or severing a web of suchmaterial to divide the web intoindividual sheets. Representative of such dispensers are those disclosedin Hamilton et al. U.S. Pat. No. 1,133,640; Schroeder U.S. Pat. No.1,449,062; Shelley U.S. Pat. No. 1,543,299; Walsh et al. U.S. Fat. No.2,278,029; and Agamaite U.S. Pat.. No. 2,560,061. The perforating orsevering mechanisms used in these dispensers generally include arotatably mountedknife and a cooperating rotatably mounted roller havinga slot therein for receiving the radially outward portion of the knifeas the knife rotates past the roller. The web of flexible sheet materialis passed between the roller and the knife to be perforated or severedwhen the radially outward knife portion enters the slot in the roller.

Such mechanisms are satisfactoryl for perforating or severing relativelyunstretchable flexible sheet materials, such as uncreped paper toweling.However, with the increased use of relatively stretchable flexible sheetmaterials, such as embossed and creped paper toweling, the prior artperforating and severing mechanisms have proved unsatisfactory becausethe web of sheet material tends to stretch about the cutting edge of theknife instead of being perforated or severed thereby. This problemresults principally from the orientation of the cutting edge during theentrance of the radially outward knife portion into the slot; thecutting edge being oriented nonparallel to the direction in which theradially outward knife portion moves with respect to the web, causingthe edge to slide'along the web. Although precision rotary shears are.known which could be employed for obviating this problem, for example,the rotary shears shown in Kalko U.S. Pat. No. 1,939,012, such shearsare much too expensive to be used in flexible sheet material dispensersdesigned for installation in both commercial and private washrooms andkitchens.

SUMMARY OF TI'IE INVENTION The perforating mechanism of the presentinvention offers an economical solution to the above-describeddeficiency of the perforating and severing mechanisms used in the priorart flexible sheet material dispensers. y

Basically described, the perforating mechanism of the inventioncomprises; a chassis, a roller rotatably mounted *onl the chassis, aknife rotatably mounted on the chassis adjacent the roller and having aradially outward portion defining a cutting edge for perforating a webof flexible sheet material as the web passes between the roller and theknife, the roller being operatively connected to the knife forsynchronous rotation therewith and having a slot therein for receivingthe radially outward knife portion as the knife rotates past the roller,and means associated with the knife for orienting the cutting edgesubstantially in the direction in which the radially outward knifeportion moves with respect to the web during the entrance of the portioninto the slot so that when the portion enters the slot the cutting edgewill effectively perforate the web.

A web guiding means preferably is employed in conjunction with theperforating mechanism which holds theweb of flexible sheet materialtautly about the roller at all times to further reduce any tendency ofthe web to stretch about the cutting edge of the knife.

The dispenser of the invention, in which the abovedescribed perforatingmechanism is adapted to be used, preferably includes an adjustable stopmechanism for stopping the rotation of the knife and the roller and thusarresting the movement of the web with the -perforations last-producedin the web either outside or inside the dispenser so that when anindividual sheet of material is tom from the web along suchlast-produced perforations, the leading edge of the web may or may notbe immediately accessible to a user, as desired.

With the foregoing in mind, it is an object of the present invention toprovide a flexible sheet material dispenser having a mechanism foreffectively perforating a web of flexible sheet material, andparticularly a web of relatively stretchable flexible sheet material.

It is also an object of the invention to provide a .mechanism forperforating a web of flexible sheet material which mechanism includes aknife and a means for orienting the cutting edge thereof in thedirection which is most eective for perforating the web.

lt is a further object of the invention to provide a flexible sheetmaterial dispenser which includes an adjustable stop mechanism forregulating the position of the leading edge of a web of flexible sheetmaterial such that the leading edge may be positioned either outside 'orinside the dispenser and thus be either immediately or not immediatelyaccessible to a user.

It is an additional object of the invention to provide a flexible. sheetmaterial dispenserhaving a ymechanism for perforating a web of flexiblesheet material, which dispenser embodies a compact and rugged structureand which is economical to manufacture, and thus is ideally suited forboth commercial and private installations.

These and other objects of the invention will become apparent upon aconsideration of the detailed description of the preferred embodimentsthereof given in connectionwith the following drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a front view ofthe dispenserof the invention;

FIG. 2 is a right end view of the dispenser shown in FIG. l;

FIG. 3 is a front view of the dispenser shown in FIG. l with the housingthereof shown in cross section;

FIG. d is a right end view of the dispenser shown inFIG. 1 with thehousing thereof shown in cross section;

FIG. 5 is a left end view of the dispenser shown in FIG. 1 with thehousing thereof shown in cross section;

FIG. b is a sectional view taken on line 6-6 of FIG.

FIG. 7 is a sectional view taken on line 7-7 of FIG. 5 with selectedelements of the dispenser being broken away from clarit FIGy. b is asectional view taken on line of FIG. 7;

FIG. 9 is a sectional view taken on line 9-9 of FIG. d;

FIG. 10 is an enlarged elevational view of the stop mechanism andassociated elements used in the dispenser shown in FIG. I;

FIG.y Il is a sectional view of one of the vacuum cups of the timingmeans used in the dispenser shown in FIG. l;

FIG. 112 is an elevational view of the knife of a first embodiment ofthe perforating mechanism of the invention, which mechanismmay be usedin the dispenser shown in FIG. l;

FIG. I3 is an elevational view of one ofthe knife mounting brackets forthe knife shown in FIG. l2;

FIG. ld is an elevational view of a knife roller assembly for rotatablysupporting the knife shown in FIG. 12;

FIG. If is an elevational view of the slot roller used in conjunctionwith the knife shown in FIG. 12;

FIG. I6 is a sectional view taken on line Io--llbl of FIG. 114;'

FIG. I7 is a sectional view taken on line I7-I' of FIG. I5;

FIG. III is an elevational view of a knife roller assembly for rotatablysupporting the knife of a second embodiment ofthe perforating Vmechanismof the invention, which mechanism also may bc used in the dispensershown in FIG. l',

FIG. 19 is an elevational view of the slot roller used in conjunctionwith the knife shown in FIG. 18;

FIG. 20 is a sectional view taken on line 20-20 of FIG. 18;

FIG. 21 is a sectional view taken on line 21-21 of FIG. 19;

FIG. 22 is a schematic sectional view of a third embodiment of theperforating mechanism of the invention, which mechanism also may be usedin the dispenser shown in FIG. 1; and

FIG. 23 is a diagrammatic sectional view showing the operation of theperforating mechanism which is comprised of the knife roller assemblyshown in FIG. 14 and the slot roller shown in FIG. 15.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The dispenser of the inventionis designated in the drawings by reference numeral 10, and basicallycomprises a chassis 12 (FIG. 3), a supporting means 14 (FIG. 6) forrotatably supporting a roll of flexible sheet material, such as a rollof creped paper toweling 150, a guiding means 16 (FIGS. 4 and forguiding a web of paper toweling 160 from roll 150 to a position to begrasped by a user so that the user may pull the web out of dispenser 10,and a perforating mechanism 18 (FIGS. S and 8) for perforating web 160at intervals therealong to divide the web into individual sheets.

The Chassis of the Housing Chassis 12 includes a backplate 20 (FIGS. 2and 4 8) which is adapted to be secured to a wall 21 (FIG. 2) bysuitable fasteners, such as screws 22. Integral with backplate 20 are aleft end flange 24 (FIG. 5) and a right end flange 26 (FIG. 4). A leftend plate 28 is aixed to left end flange 24 by suitable fasteners, suchas sheet metal screws 30. A right end plate 32 is similarly affixed toright end flange 26 by suitable fasteners, such as sheet metal screws34. A bottom plate 36 (FIGS. 4, 5, 7 and 8) extends forwardly from thebottom of backplate 20 and curves upwardly near the front of thedispenser, terminating in an upstanding arcuate portion 38. The rearportion of bottom plate 36 has a plurality of holes 40 therein whichregister with a corresponding plurality of lugs 42 that are carried by abottom flange 44 integral with backplate 20. Also, the rear portion ofbottom plate 36 is connected to left end plate 28 and right end plate 32by tabs 29 and 33, respectively; the tabs being integral with the endplates and being spot welded to the bottom plate. The forward portion ofbottom plate 36 is connected to left end plate 28 by tabs 46, 47 and 48(FIG. 5) and to right end plate 32 by tabs 50, 51 and 52 (FIG. 8); thetabs being integral with the bottom plate and being spot welded to theend plates. A plurality of louvers 54 (FIGS. 7 and 8) are formed inbottom plate 36 to permit air to circulate within dispenser 10.

Chassis 12 also includes a stripper 56 (FIGS. 3, 5, 7 and 8) having aplurality of upstanding arcuate fingers 58, the function of which isdescribed below, and which is attached to left end plate 28 and to rightend plate 32 by tabs 60 and 62, respectively; the tabs being integralwith the stripper and being spot welded to the end plates. An arcuateshield 64 (FIGS. 5, 7 and 8) extends upwardly from approximately themidpoint of bottom plate 36 and forwardly to the upward extremity ofarcuate bottom plate portion 38. The lower portion of shield 64 isdefined by a flange 66 having a plurality of holes 68 therein whichregister with a corresponding plurality of lugs 70 carried by bottomplate 36. The upper portion of shield 64 is connected to left end plate28 by tabs 72 and 74, and to right end plate 32 by tabs 76 and 78; thetabs being integral with the shield and being attached to the end platesby suitable fasteners, such as sheet metal screws 80. Shield 64 andbottom plate 36 define an elongated cavity 82 within dispenser withinwhich guiding means 16 and perforating mechanism I8 are disposed. Theright end of cavity 82 is enclosed by right end plate 32 and the leftend of the cavity is enclosed by a cover plate 84 (FIGS. 5 and 7). Coverplate 84 is connected to left end plate 28 by a plurality of suitablefasteners, such as sheet metal screws 86 which engage a correspondingplurality of bosses 88 formed in the end plate. A removable cover plate,such as plate 84, is used for enclosing the left end of cavity 82 sothat access readily may be had to the interior of the cavity forservicing guiding means 16 and perforating mechanism 18.

Chassis 12 is enclosed by a housing 90 (FIGS. 1 and 2). Housing 90comprises an upper portion 92, a cap portion 94, a lower front portion96, a lower left end portion 98, and a lower right end portion 100. Capportion 94 is attached (FIGS. upper portion 92 by a plurality of tabs102 (FIGS. 4 and 5). The other portions of the housing are connectedtogether in an appropriate manner, such as by spot welding the portionstogether where the edges thereof overlap. Lower front portion 96 definesan opening 104 through which web 160 (FIG. 3) may be withdrawn fromdispenser 10 by a user, as described below. Lower left and right endportions 98 and 100 each include an integral bottom flange (FIGS. 3--5,8 and 9) which is adapted to enclose the respective left or right outerportions of bottom plate 36.

Housing 90 is connected to chassis 12 by pivot pins 106 and 108; pin 106pivotally connecting lower left end housing portion 98 to left endflange 24 of backplate 20, and pin 108 pivotally connecting lower rightend housing portion 100 to right end flange 26 of backplate 20. Thisarrangement permits housing 90 to be pivoted outwardly about pins 106and 108 away from chassis 12 to expose the internal elements ofdispenser 10. A lock 110 preferably is attached to the rear of capportion 94 for releasably securing the housing the chassis to preventunauthorized access to the interior of the dispenser. Lock 110preferably is a combination locking and latching device of the typedisclosed in U.S. Pat. No. 3,500,667, and owned by the assignee ofthepresent application.

The Supporting Means Supporting means 14 comprises a pair ofsubstantially horizontally opposed supporting members 110 and 112 (FIGS.3-6). Supporting member 110 (FIGS. 3, 5 and 6) is mounted at the leftend of chassis 12 and includes a mounting bracket 114 and a hub 116.Mounting bracket 114 is attached to backplate 20 and left end flange 24by suitable fasteners, such as sheet metal screws 118. Hub 116 isattached to the forward end of bracket 114 by suitable fasteners, suchas sheet metal screws 120. I-Iub 116 has a recess 122 therein defined byan arcuate bearing surface 124 and the arcuate innner edge of a guidelip 126.

Supporting member 112 (FIGS. 3, 4 and 6) is mounted at the right end ofchassis 12 and includes a flexible mounting bracket 128 and a hub 130.Mounting bracket 128 is attached to backplate 20 by suitable fasteners,such as sheet metal screws 132. I-Iub 130 is attached to the forward endof bracket 128 by suitable fasteners, such as sheet metal screws 134,and carries a pair of lugs 136 which register with a corresponding pairof slots formed in the bracket. Hub 130, similarly to hub 116, has arecess 138 therein defined by an arcuate bearing surface 140 and theinner arcuate edge of a guide lip 142.

A braking spring 144 has one end affixed to the inner surface of hub 130by a suitable fastener, such as rivet 146, and extends rearwardly fromhub 130, between luga 136, and terminates adjacent backplate 20.

Supporting means 14 is adapted to rotatably support roll 150. The rollpreferably is of the type disclosed as the first embodiment (FIGS. 1-3)in U.S. Pat. No. 3,438,589, and owned by the assignee of the presentapplication. The roll has a structurally rigid internal supporting means152 comprising a cylindrical core 154 and a pair of trunnion members 156and 158 attached to the ends of the core. The outer ends of trunnionmembers 156 and 158 extend axially outwardly beyond the ends of roll150, and are adapted to engage recesses 122 and 138, respectively. Theouter ends of the trunnion members have different cross-sectionaldimensions; and recesses 122 and 138 have different internal dimensionscorresponding to the cross-sectional dimensions of the outer ends of thetrunnion members. Thus, roll may be supported by supporting means 14only when each recess is engaged by the trunnion member outer end havinga crosssectional dimension corresponding to the internal dimension ofthat recess; and specifically only when recess 122 is engaged by theouter end of trunnion member 156 and recess 135 is engaged by the outerend of trunnion member 155. This feature ensures that roll 155 will beplaced in dispenser 10 in the proper manner for web 165 to be passedthrough guiding means 16 and perforating mechanism 15, and out of thedispenser through opening 11111.

To insert roll 1511 into supporting means 1d, the outer ends of trunnionmembers 156 and 155 are placed against guide lips 126 and 162,respectively, and the roll is then pushed rearwardly. When this occursbracket 125 will flex outwardly permitting the outer ends of thetrunnion members to engage,

and seat in, recesses 122 and 135. After the roll has been thus insertedinto the supporting means, flexible mounting bracket 125 urges hub 135toward hub 116 to prevent any inadvertent disengagement of the roll.

As the roll is inserted into the supporting means, the roll end nearestspring 1166 will contact the spring and move the spring outwardly to theposition shown in solid lines in FIG. 6. Thereafter, as web 1611 iswithdrawn from the roll, spring 1M will frictionally engage the roll endand brake the rotation of the roll, to thus prevent uncontrolledspinning thereof.

The Guiding Means and the Perforatng Mechanism Guiding means 16 includesan upper pinch roll 162 and a lower pinch roll 166 (FIGS. 3-5 and ll).Upper pinch roll 162 is mounted on stub shafts 166 and 165 which arejournaled for rotation in cover plate 56 and right end plate 32,respectively. Similarly, lower pinch roll 16d is mounted on stub shafts175 and 172 which are also journaled for rotation in cover plate 541 andright end plate 32, respectively.

Perforating mechanism includes a roller 171 (FIGS. 3- 5, 7, 5, 15 and17) which is positioned between pinch rolls 162 and 1611 and which hasan intermittent helical slot 176 therein. Slot 176 extends generallyaxially of roller 174 and opens radially outwardly from the surfacethereof. The slot roller is supported by stub shafts 175 and 150 whichare journaled for rotation in cover plate 56 and right end plate 32,respectively. Perforating mechanism 15 also includes a knife 152 whichis rotatably mounted by a roller 15d. Roller 154 is supported by stubshafts 156 and 155 which are journaled for rotation in cover plate 56and right end plate 32, respectively. The bearing surfaces for shafts175, 156, 150 and 155 preferably comprise low-friction bushings 191),194, 192 and 196, respectively; the former two bushings being secured tocover plate 5d and the latter two to right end plate 32.

Stub shafts 166, 1711, 165 and 172 are journaled by elongated bearingsurfaces 195, 252, 255 and 21M, respectively; the former two surfacesbeing integrally formed in cover plate 56 and the latter two beingintegrally formed in right end plate 32. This arrangement permits eachof the pinch rolls to move into contact with slot roller 17d to form anip therebetween. A biasing spring 256 is connected to stub shafts 1166and 175, and a similar biasing spring 255 is connected to stub shafts165 and 172 for urging the pinch rolls toward the slot roller. Biasingsprings 256 and 255 are held in position by U-shaped brackets 215, oneof which is attached to cover plate 55 and another of which is attachedto right end plate 32 in any convenient manner, such as by spot welding.In order to permit the surfaces of lower pinch roll 166 and slot roller174 to contact one another, the upstanding arcuate portion 35 of bottomplate 36 comprises a plurality of spaced apart, relatively narrowarcuate strips 212 (FIG. 7), and pinch roll 166 has a plurality ofcircumferential slots 2141 therein (FIG. 3), within which strips 212 areaccommodated.

From roll 151i, web 160 is directed around upper pinch roll 162, betweenthe upper pinch roll and slot roller 176, around the slot roller,between the slot roller and lower pinch roll 166, around the lower pinchroll and out of the dispenser through opening 1511. As will be apparentform the foregoing description, pinch rolls 162 and 16d ensure that web160 will be held tautly about slot roller 176 at all times. When a userwithdraws the web from the dispenser by exerting a pulling force on theleading edge thereof, pinch roll 166 will move slightly out of contactwith slot roller 1741; however, as soon as the pulling force is relaxedbiasing springs 206 and 205 will v immediately move the pinch roll backinto contact with the slot roller.

Slot roller 17.41 also has a plurality of circumferential slots 216therein, within which are accommodated fingers 55 of stripper 56.Fingers 55 ensure that web 160 will be directed out of opening 10dinstead of adhering to the slot roller and becoming wound thereabout.

Knife 152 is helically twisted along the length thereof and includes aradially outward portion 217 which is curved forwardly in the directionof rotation of the knife and which defines a serrated cutting edge 220(FIGS. d, 5, 7, 5, 12, 14 and 16). The knife also has a plurality ofnotches 218 therein within which strips 212 of bottom plate portion 35are accommodated as the knife rotates into proximity with and past slotroller 17d. As the knife rotates past the slot roller, radially outwardknife portion 217 enters slot 176 and cutting edge 221) progressivelyperforates the entire width of web 165 except for the sections of theweb that are aligned with notches 215. The unperforated sections of theweb have sufficient tensile strength to permita user to draw the web outof the dispenser by exerting a smooth, continuous pulling force thereon.However, after the web has been perforated, an abrupt increase in thepulling force will cause the web to part along the perforationslast-produced therein by cutting edge 220.

Knife 152 is attached to knife roller 154 by a pair of mounting brackets222. The knife is first affixed to the mounting brackets, convenientlyby welding, and a helical twist is then imparted to the knife and thebrackets. The brackets are thereafter attached to roller 154 by aplurality of bolts 2201 which threadably engage a pair of hubs 226disposed internally of the roller at the ends thereof. The knife andmounting brackets are bowed slightly outwardly at the centers thereof(FIGS. 12 and 23) so that after helical twist is imparted thereto, theentirety of the radially inward surfaces thereof will abut the surfaceof roller 154. Additional bolts 2211 may be used for securing roller 154to hubs 226 to ensure that the hubs are firmly anchored within theroller.

Slot roller 174 and knife roller 154 are operatively interconnected toensure that the rollers will rotate in synchronism with one another. Forthis purpose a gear 226 is affixed to one end of the slot roller-whichengages and meshes with a gear 225 affixed to the same end of the kniferoller. In the embodiment shown in the drawings, gear 225 has twice asmany teeth as does gear 226, so that the slot roller will rotate attwice the rotational speed of the knife roller. Due to this differencein the rotation speeds of the two rollers, slot 176 must be twistedthrough an arc which is twice as large as the arc through which knife152 is twisted. Thus, the knife may be helically twisted through an arcof 45 (FIG. 16) and slot 176 helically twisted through an arc of (FIG.17).

To preclude slippage of web about the slot roller, the roller preferablyis made from a substance having a relatively high coefficient offriction, such as rubber. When a user exerts a pulling force on theleading edge of the web, the frictional force exerted by the web on theslot roller causes the slot and knife roller to rotate in synchronismwith one another.

The path of movement of cutting edge 220 with respect to slot 176 duringthe perforating cycle of the knife is shown in FlG. 23 by dashed line221. Also shown in this FIG. are the relative positions of edge 220 anda point 225 on the knife located at the radially outward extremity ofbrackets 222'; the positions of the former by points 0', 2', 41', 6',5', 10', 12', 1d', 16', and 15', and the corresponding positions of thelatter by points 5", 2,6, 6",5",115",12",1d', 16' and 15'.

The positions of radially outward knife portion 217 with respect to slot176 during the perforating cy'cle are indicated by the broken lineswhich connect the corresponding positional points of edge 225 and point225 i.e., lines 11'41",

21-211 41411, 6/ 61/y 8r 8lry 10i-10H l2l 12rl l4l l4ll 16'16x and18'-18". As shown, while portion 217 is moving from position '0" toposition 6'-6", i.e., during the entrance ofthe portion into slot 176,cutting edge 220 is oriented substantially in the same direction as thedirection in which portion 217 is moving.

The same relationship between the orientation of the cutting edge andthe movement of portion 217 is maintained with respect to web 160 as ismaintained with respect to slot 176. Thus, as described above, web 160is held tautly about slot roller 174 by pinch rolls 162 and 164 and bythe pulling force exerted on the web by a user. As a consequence of thisfeature, when slot 176 rotates into proximity with knife 220 the portionof the web which overlies the slot is curved in conformance with thecurvature ofthe surface of roller 174, and there is no relative movementtherebetween. Thereafter, when portion 217 reaches position 0"-0" andslot 176 reaches the position shown in FIG. 23, i.e., when cutting edge220 initially contacts web 160, the orientation of the cutting edgesubstantially coincides with the direction in which portion 217 ismoving with respect to the web. This relationship is maintained asportion 217 moves from position 0'0" to position 6'6", i.e., during theentrance of the portion into the slot. Thus, the forward curvature ofportion 217 orients cutting edge 220 substantially in the direction inwhich portion 217 moves with respect to the web, as well as with respectto slot 176, during the entrance of the portion into the slot.

The structure and resulting operation of perforating mechanism 18provides several advantages over the prior art perforating and severingmechanisms. The orientation of the cutting edge results in an effectiveperforation of the flexible sheet material web by reducing any tendencyof the edge to slide along the web. Also, the mechanism is economical tomanufacture, and embodies a rugged and compact structure which is ableto withstand the prolonged and abusive wear encountered in commercialwashroom and kitchen installations.

The Stop Mechanism and the Timing Means Dispenser also includes amechanism 233 (FIGS. 4 and 10) for stopping the rotation of knife roller184 and slot roller 176 abruptly and thus arresting the movement of web160 abruptly, so that an individual sheet of paper toweling may be tornfrom web 160 along the perforations last-produced therein by knife 182.Stop mechanism 233 includes stop lever 230 which is pivotally connectedto right end plate 32 by a pivot pin 232 and has a cam follower 234 anda stop lug 236 integrally affixed thereto. The stop mechanism alsoincludes a feed wheel 240 which is secured to the end of stub shaft 188,being one of the shafts which support knife roller 184, and has aCamming pin 238 affixed thereto. Camming pin 238 is adapted to coactwith camming pin 234 and stop lug 236 to stop the rotation of kniferoller 184 and slot roller 174. As the knife roller is rotated incidentto the exertion ofa pulling force on web 160 by a user, camming pin 238is rotated about the axis of shaft 188. While the knife roller isrotating, stop lever 230, cam follower 234 and stop lug 236 are in thepositions shown in full lines in FIG. 10. In this position, the camfollower is positioned in the rotational path of Camming pin 238, sothat when the pin reaches the position shown in full lines in FIG. 10,it engages the underside of, and cams the follower upwardly. This actionpivots stop lever 230, cam follower 234 and stop lug 236 to thepositions shown in dotted lines in FIG. 10. In this position, the stoplug is positioned in the rotational path of camming pin 238, so thatwhen the pin disengages the underside of the cam follower, it thereafterengages the stop lug. This causes knife roller 184 and slot roller 174to stop abruptly and thus abruptly arrests the movement of web 160,resulting in an abrupt increase in the pulling force exerted on the web.As explained above, this permits an individual sheet of paper towelingto be torn from the web along the perforations last-produced therein byknife 182.

A timing means 237 is associated with stop mechanism 233 for regulatingthe length of time during which the stop mechanism is effective forpreventing the rotation of the knife and slot rollers. Timing means 237comprises a pair of opposed, resilient vacuum cups 242 and 244', cup 242being connected by a bracket 246 to stop lever 230 and cup 244 beingattached by a mount 248 to a flange integral with right end plate 32.When camming pin 238 engages the underside of cam follower 234 andpivots stop lever 230 upwardly to position stop lug 236 in therotational path of the Camming pin, vacuum cup 242 is pivoted rearwardlyinto vacuumgripping relationship with cup 244. As long as cups 242 and244 remain in vacuum-gripping relationship, stop lug 236 will remain inthe rotational path ofcamming pin 238 and prevent knife roller 184 andslot roller 174 from being rotated.

Preferably, vacuum cup 242 is made of a relatively hard resilientmaterial, such as hard rubber; and vacuum cup 244 is made ofa relativelysoft resilient material, such as soft rubber. This arrangement minimizesthe compression force required to engage the cups in vacuum-grippingrelationship, yet provides a sufficient vacuum-gripping force betweenthe cups, i.e., the force required to pull the cups apart, to ensurethat the cups will not be pulled apart when Camming pin 238 engages stoplug 236. The resiliency of cups 242 and 244, and particularly ofrelatively soft resilient cup 244, provides a cushion for absorbing thedynamic forces generated by the abrupt engagement of pin 238 with lug236 and thus minimizes wearing of the stop mechanism components.

To regulate the period of time during which cups 242 and 244 remain invacuum-gripping relationship, a needle valve 250 (FIG. l1) is providedfor controlling the flow of ambient air into the vacuum environmentbetween the cups. Valve 250 is mounted in bracket 246 and communicateswith the interior of cup 242. The valve includes a cylindrical valvebody 252 having an aperture 253 formed therein, and a needle-tippedadjustment bolt 254 which threadably engages an end flange of bracket246. Bolt 254 is locked into position by a lock nut 255 which is alsothreadably engaged by the bolt and which abuts the end flange of bracket246. By adjusting the position of bolt 254 with respect to aperture 253,the rate at which ambient air flows into the vacuum environment betweenvacuum cups 242 and 244, and thus the period of time during which thecups remain in vacuum-gripping relationship, may be regulated. A returnspring 256 is connected between bracket 246 and the forward portion ofright end plate 32 for pivotingstop lever 230 downwardly, and thusmoving stop lug 236 out of the rotational path of Camming pin 238, whenthe air pressure within the environment between vacuum cups 242 and 244has increased sufficiently to destroy the vacuumgripping relationshipbetween the cups. The user may thereafter withdraw a further length ofweb from the dispenser, which will be perforated by knife 182 in themanner described above and which may be torn from the web as anindividual sheet of paper toweling when stop mechanism 233 again stopsthe rotation of knife roller 184 and slot roller 174.

As mentioned above, feed wheel 240 is secured to the end of stub shaft188. Preferably, the wheel is secured to the shaft by a bolt (not shown)which threadably engages the shaft axially thereof. The cross section ofthe end of shaft 188 is shaped as an equilateral triangle (FIGS. 4 and10), and feed wheel 240 has a similarly shaped opening in the centerthereof for accommodating the shaft end therein. The feed wheel may thusbe secured to shaft 188 in any one of three rotational positions. In onerotational position of the feed wheel (FIG. 4) Camming pin 238 engagesstop lug 236 and the rotation of the knife and slot rollers stoppedbefore the perforations lastproduced in web 160, indicated at P, havebeen drawn outside dispenser 10. After a user has torn an individualsheet ofpaper toweling from the web with the last-produced perforationsinside the dispenser, the leading edge of the web will thereafter bepositioned within the dispenser and thus not be immediately accessibleto the user. This mode of operation encourages economical consumption ofroll 150.

After the time period has elapsed during which timing means 237maintains stop mechanism 233 effective for preventing the rotation ofthe knife and slot rollers, the knife and slot rollers are rotatedautomatically by a feed means 258 to move the leading edge of the weboutside the dispenser. Feed means 258 comprises a lug 260 affixed tofeed wheel 240 and a feed spring 262 connected between lug 260 and therear portion of right end plate 32. Lug 260 is positioned with respectto camming pin 238 so that spring 262 will be extended when the cammingpin engages stop lug 236 (FIGA 4). Thus, when the stop lug is moved outof the rotational path of pin 238 by return spring 256, feed spring 262will contract and thereby impart rotation to feed wheel 240 and shaft188. Shaft 188 in turn will impart rotation to knife roller 184 and slotroller 174, thus moving the leading edge of web 160 outside thedispenser.

In the second rotational position of feed wheel 240 with respect toshaft 188 (FIG. 8), stop mechanism 233 will stop the rotation of theknife and slot rollers after the perforations last-produced in web 160,indicated at P are outside dispenser 10. In this mode of operation, theleading edge of Y the web is immediately accessible to a user after anindividual sheet of toweling has been torn therefrom along theperforations last-produced therein. When this mode of operation isemployed, bolt 254 preferably is adjusted so that the time period duringwhich the stop mechanism is effective for stopping the rotation of theknife andpinch rollers is of short duration, i.e., 1-2 seconds,permitting a second sheet of toweling to be obtainable as soon as thefirst sheet is torn from the web. As is apparent, this second mode ofoperation is less economical than the first mode, but is more convenientto the users needs than the first mode. The first mode generally wouldbe employed where economical consumption of the paper toweling is asignificant factor, such as in commercial washroom installations, andthe second mode employed where` user convenience is a significantfactor, such as in a private kitchen installation. Dispenser 10 is thusideally suited for either commercial or private installations.

The third rotational position of feed wheel 240 with respect to shaft188 is not used because in this latter position, knife portion 217 wouldbe within slot 176 when the stop mechanism stopped the rotation of theknife and slot rollers. This would not only permit the web to be atleast partially torn along the perforations being produced therein asthat time, thus dividing the web before the perforations have passedbetween slot roller 174 and lower pinch roll 164, but also would imposeundesirable bending forces on blade 182.

Dispenser l0 also includes a means 265 for rotatably supporting apartially consumed roll of flexible sheet material, such as a partiallyconsumed roll on creped paper toweling 264 (FIG. 8). Supporting means265 comprises a pair of opposed flanges 266 and 268, which are integralwith backplate (FIGS. 4, 5, 7 and 8). Flanges 266 and 268 extendforwardly from backplate 20 into a cavity 270 in the lower rear portionof the dispenser defined by the backplate, bottom plate 36 and shield64. Each of the flanges has a U- shaped cutout therein; flange 266having cutout 272 therein and flange 268 having cutout 274 therein. Theinternal dimensions of cutouts 272 and 274 correspond to thecrosssectional dimensions of the outer ends of trunnion members 156 and158, respectively. Thus, after roll 150 has been partially consumed,being then designated roll 264, the roll may be moved from supportingmeans 14 to supporting means 265. When the roll is moved from supportingmeans 14 to supporting means 265, it is not necessary to withdraw web160 from guiding means 16 and perforating mechanism 18. The trunnionmembers are simply disengaged from supporting members 110 and 112 andinserted into cutouts 272 and 274. From this latter position the webextends along path 276 (FIG. 8) from the top of roll 264 to the top ofupper pinch roller 162.

After partially consumed roll 264 has been moved into cavity 270, afresh roll 150 may be inserted into supporting lill means 14 in themanner described above. The web from roll is merely superimposed on theweb from roll 264 and is passed through guiding means 16 and perforatingmechanism 18 in the manner described above. Thereafter, as long as anypaper toweling remains wound about partially consumed roll 264,dispenser 10 will dispense a double-ply thickness of the toweling.

This latter feature of the dispenser is particularly suited forcommercial installations where it is uneconomical to service thedispenser except at regular intervals, such a daily. In such instances,a custodian need not wait until a roll is completely consumed beforeservicing the dispenser, nor need he discard a partially consumed rollwhen servicing the dispenser at the end of a regularly establishedservice interval. I-Ie merely moves the partially consumed roll fromsupporting means 14 to supporting means 265, and inserts a fresh rollinto the former supporting means. To facilitate the custodians appraisalas to whether or not a fresh roll need be placed in the dispenser at theend of a regularly established service interval, viewing ports 278 (FIG.2) are provided in upper housing portion 92 adjacent an end of roll 150.By observing the diameter of the roll through ports 278, the custodianwill be appraised of the amount of toweling remaining on the roll.

To load dispenser l0, housing 90 is first pivoted outwardly from aboutchassis 12, thus exposing the interval elements of the dispenser. A rollof flexible sheet material, such as roll 150, is then inserted intosupporting means 14 as described above. The web from the roll, such asweb 160, is directed around upper pinch roll 162, with the leading edgeof the web resting on the forwardsurface of slot roller 174. Housing 90is then pivoted upwardly about chassis l2 to enclose the internalelements of the dispenser. Feed wheel 240 is thereafter turned in acounterclockwise direction as viewed from the right end of thedispenser, causing the web to be fed through guiding means 16 andperforating mechanism 18. Arcuate strips 212 and lower pinch roll 164insure that the web will be guided, and held tautly, about slot roller174. To permit the feed wheel to be manipulated when the internalelements of the dispenser are enclosed by housing 90, a slot 280 isprovided in lower right end housing portion 100, through which the lowerportion of feed wheel 240 extends (FIG. 4).

Dispenser 10 also includes means for preventing feed wheel 240 frombeing rotated in the direction opposite to the proper direction forfeeding web through the guiding means and the perforating mechanism.Such means include a ratchet mechanism 282 (FIG. 4) comprising anL-shaped pawl 284 which is pivotally connected to right end plate 32 bya pin 286. Inserted over the base of the pawl is a resilient sleeve 288which engages a plurality of notches 290 formed in the periphery of feedwheel 240. As long as the feed wheel is rotated in the counterclockwisedirection as viewed from the right end of dispenser 10, the base of pawl284 and sleeve 288 pivot freely in and out of notches 290. However, anyattempt to rotate the feed wheel in the opposite direction will causethe pawl to bind in one of the notches and prevent rotation of thewheel. A lug 292 carried by right end plate 32 is positioned above pawl284 to prevent the pawl from rotating completely about pin 286, thusensuring that the pawl will remain in the proper position with respectto feed wheel 240 to prevent improper rotation of the wheel.

The Second Embodiment of the Perforating Mechanism A second embodimentof the perforating mechanism of the invention is shown in FIGS. 18-21.This latter embodiment of the perforating mechanism may be employed indispenser 10 instead of mechanism 18, and includes an axially straightknife 308 which is attached to axially straight mounting brackets 302.In all other respects the knife roller assembly of the second embodimentis identical to the knife roller assembly of the first embodiment,including knife roller 184, stub shafts 186 and 188, and gear 228.

A slot roller 303 is used in conjunction with knife 300. Roller 303 issimilar to slot roller 174, except that instead of an intermittenthelical slot along the length thereof, roller 303 has an intermittentaxially straight slot 304 therein for accommodating the radially outwardportion of knife 300.

The only difference in operation between the first and secondperforating mechanism embodiments is that helically twisted knife 182 ofthe first embodiment perforates the web progressively, with only a smallsection of the cutting edge contacting the web at any one time. Thisarrangement requires only a relatively small force to be exerted againstthe web by the cutting edge to accomplish an effective perforation. Thecutting edge of knife 300, on the other hand, perforates the entirewidth ofthe web at one time, requiring a slightly greater perforatingforce. The advantage of the second embodiment over the first is that thelatter is somewhat more economical to manufacture, since the knife andmounting brackets need not be helically twisted.

The Third Embodiment of the Perforating Mechanism A third embodiment ofthe perforating mechanism of the invention is shown in FIG. 22. Thisembodiment also may be employed in dispenser l instead of the first orsecond embodiments described above. The third embodiment of theperforating mechanism includes a substantially planar knife 306 which ispivotally mounted on a knife roller 308 by a pair of stub shafts 310afxed to each end of the knife and journaled in the ends of the kniferoller. Also affixed to each end of knife 306 are camming lugs 312 whichextend radially outwardly beyond the cutting edge o'f the knife. Lugs312 are adapted to be engaged by cams 314 mounted on each end of a slotroller 316 having an axial slot 318 therein. As opposed to the previousembodiments, the surfaces of the knife roller 308 and slot roller 316contact each other, thereby eliminating the necessity for a lower pinchroll for maintaining web 160 taut about the slot roller.

Knife 306 is normally biased forwardly by a small spring (not shown)through an arc of approximately from a radial orientation with respectto roller 308. Thus, when the knife enters slot 310, the cutting edgethereof will be oriented substantially in the same direction as thedirection in which the radially outward portion of the knife is movingwith respect to web 106. ln this respect, the perforating action ofknife 306 is similar to the perforating action of knives 182 and 300,described above.

After knife 306 moves into the slot, lugs 312 will be engaged by cams314. The cams pivot the lugs, and therefore knife 306, rearwardly withrespect to the direction of rotation of knife roller 308. This actionpermits slot 318 to be made narrow enough for the knife to perform aneffective perforation while maintaining the surfaces of the knife andslot rollers in contact with each other. After the knife has beenwithdrawn from the slot and lugs 312 have disengaged cams 314, thebiasing spring will again pivot knife 306 forwardly. To ensure thatknife roller 308 and slot roller 316 rotate in synchronism with eachother, the rollers preferably are operatively connected together bygears, as described above in connection with the first and secondperforating mechanism embodiments.

The foregoing constitutes a detailed description of the dispenser andperforating mechanism of the invention, the latter being adapted to beused in the former, although not being restricted to use solely therein.Moreover, it is recognized that various modifications of both thedispenser and perforating mechanism of the invention may occur to thoseskilled in the art. Therefore the scope of the invention is to belimited solely by the scope of the appended claims.

We claim:

l. A method for dispensing flexible sheet material from a dispenserhaving a roll of said material rotatably supported therein, said methodcomprising the steps of:

moving the leading edge of a web of said material outside the dispenserto a position to be grasped by a luser independently of a user touchingthe dispenser;

applying a pulling force adjacent said leading edge to pull the web fromthe dispenser;

perforating the web substantially transversely thereof while the web isbeing pulled fr om the dispenser; and abruptly applying an arrestingforce to the web between said roll and the perforations formed in theweb by said perforating step to abruptly stop the web so that a sheet ofsaid material is torn from the web along said perforations.

2. A method as recited in claim 1; wherein said arresting force isapplied to the web while said perforations are inside the dispenser sothat after said sheet is torn from the web, said leading edge will beinside the dispenser and inaccessible to a user; and wherein saidleading edge is moved outside the dispenser to a position to be graspedby a user a predetermined length of time after the web is abruptlystopped so that said leading edge is again accessible to a user aftersaid predetermined length of time.

3. A method as recited in claim l, wherein said arresting force isapplied to the web after said perforations are outside the dispenser sothat after said sheet is torn from the web, said leading edge is outsidethe dispenser and immediately accessible to a user, whereby said leadingedge is moved outside the dispenser to a position to be grasped by auser upon the dispensing of the previous sheet of said material from thedispenser.

1. A method for dispensing flexible sheet material from a dispenserhaving a roll of said material rotatably supported therein, said methodcomprising the steps of: moving the leading edge of a web of saidmaterial outside the dispenser to a position to be grasped by a userindependently of a user touching the dispenser; applying a pulling forceadjacent said leading edge to pull the web from the dispenser;perforating the web substantially transversely thereof while the web isbeing pulled from the dispenser; and abruptly applying an arrestingforce to the web between said roll and the perforations formed iN theweb by said perforating step to abruptly stop the web so that a sheet ofsaid material is torn from the web along said perforations.
 2. A methodas recited in claim 1; wherein said arresting force is applied to theweb while said perforations are inside the dispenser so that after saidsheet is torn from the web, said leading edge will be inside thedispenser and inaccessible to a user; and wherein said leading edge ismoved outside the dispenser to a position to be grasped by a user apredetermined length of time after the web is abruptly stopped so thatsaid leading edge is again accessible to a user after said predeterminedlength of time.
 3. A method as recited in claim 1, wherein saidarresting force is applied to the web after said perforations areoutside the dispenser so that after said sheet is torn from the web,said leading edge is outside the dispenser and immediately accessible toa user, whereby said leading edge is moved outside the dispenser to aposition to be grasped by a user upon the dispensing of the previoussheet of said material from the dispenser.